Corrupt formula?
 

Hi:

I have a formula in Excel 2002 - using XP that used to work and now I have
to take my cursor and touch the formula in the formula bar at the top of the
screen and then hit enter which causes the calculation to take place. The
formula is simple =sum( f11-e12). I have this formula is several different
worksheets and it happens in all of them. Help!!
Tricia